The Bay Area jury who found accused serial killer Joseph Naso guilty of killing four women in California between 1977 and 1994 in a notorious series of killings known as the "alphabet murders" is now being asked to decide if he should die for his crimes.

The sentencing phase of the trial began Wednesday morning in Marin County and is expected to last several weeks.

Naso was convicted of murdering Roxene Roggasch, 18, whose body was dumped in Fairfax in 1977; Carmen Colon, 22, who was found near Port Costa in 1978; Pamela Parsons, 38, who was found in Yuba County in 1993; and Tracy Tafoya, 31, who was found in Yuba County in 1994.

"I don't deserve the death penalty," Naso said.

The same jury found Naso guilty of four counts of first-degree murder, as well as the special circumstance of committing multiple murders, which makes him eligible for the death penalty.

"I should not get the death penalty because I have a lot of reverence for life. I care about others," Naso told the jury Wednesday.

He said he's been an advocate for the mentally ill and has been active in the national alliance for the mentally ill.

He said he's visited a lot of facilities and hospitals and has seen a lot. "I do what I can for those who need help," Naso said. "I care about people. I will continue to care about people. For the rest of my life I will continue to care about people who need help."

He says he'd rather help others than go on vacation. "A good time for me, a vacation for me is to help somebody who needs help. It's the gift of giving. That's better than taking a vacation," Naso said.

He admitted he's not perfect. "I've made mistakes in my life", but added that his "good days and good relationships far outweigh the few people are talking about."

Even if Naso is sentenced to death, it is unlikely he will be executed. There are 725 inmates already on California's Death Row and executions have been on hold since 2006, when a federal judge ordered an overhaul of California's execution protocol.